This Low Carb Tuna Casserole (With Cauliflower) is the perfect comfort food meal! It’s easy to prepare, comes together in one casserole dish, and is packed with protein, veggies and we’ve offered two versions to make it low-carb with or without gluten-free pasta. Made in partnership with my friends at Genova Seafood.

Low Carb Tuna Casserole (With Cauliflower)

Tuna casserole is such a classic comfort food! It’s creamy, cheesy and delicious but typically loaded with pasta and processed condensed soup! No hate on that version, but we decided it was time to re-make this dish making it gluten-free and low-carb. We tested two versions, one with pasta and one without so you can choose what amount of carbs you’d like!

For the lower carb version, we use half cauliflower and half brown rice pasta. This version is a bit more kid-friendly and has more of a classic feel to it. For our low carb version we completely swapped out the pasta for cauliflower to keep all that decadent creaminess  without any of the guilt for all of those on a low carb diet (oh hey keto diet). Either way, with whatever version you choose, you’re going to be satisfied after eating this tuna noodle casserole!

Of course we made this in partnernship with my friends at Genova Seafood. They are my favorite, trusted tuna company. Genova sources 100% of their tuna from fisheries that are MSC certified, meaning their tuna is sustainably sourced! It honestly is the best premium tuna in the purest olive oil. It is my favorite tasting tuna out there! Always non-GMO, wild-caught, and has 14g of protein in every serving!

MSC certified products must meet rigorous standards for sustainable fishing practices, like limiting by-catch (unwanted fish), avoiding overfishing and protecting marine environments. Today, only 12% of global wild caught seafood is MSC certified, and Genova Seafood is one of the companies working hard to make a change!

How do you make homemade tuna noodle casserole?

It’s simple:

1. If you’re making the pasta version you boil the pasta until al dente.
2. Saute your aromatics. Here we are using onion, celery and garlic.
3. Make your base cheese-y sauce (also called a béchamel), using gluten-free ingredients, of course.
4. Add in the cauliflower and cooked pasta (if using) and bake! We love using an oven safe pan to both start the casserole on the stove and then finish in the oven.

Cooking tools we used with this recipe:

• Heavy Bottom Pan (We use one that doubles as an oven safe dish to keep the clean-up minimal)
• Whisk
• Spatula

Want other tuna recipes? Try these favorites:

• Sweet Potato Tuna Melts
• Mediterranean Tuna Salad
• Loaded Egg Salad
• Paleo Tuna Cakes with Roasted Red Pepper Sauce

Low Carb Tuna Casserole (With Cauliflower

Print shopping list

Prep Time 00:10 Cook Time 00:30 Total Time 00:40 Serves 4-6

4.8 rating

4 reviews

Ingredients

• 2 tablespoons butter
• 1 onion, diced
• 2 celery stalks, diced
• 3 cloves garlic
• 3 tablespoon arrowroot
• 2-1/2 cups cashew milk (or milk of choice)
• 1 tablespoon dijon mustard
• 1 teaspoon ground black pepper
• 1 teaspoon fine sea salt
• 1/2 teaspoon paprika
• pinch cayenne (optional)
• 1/2 cauliflower, about 1 lb., cut into florets (For Low Carb Version use 1 whole cauliflower, about 2-2-1/2 pounds and slice into pieces about 1/4" thick)
• 2-4oz cans genova tuna, drained
• 6 ounces brown rice pasta, cooked al dente (For Low Carb Version Omit This)
• 1/3 cup frozen green peas (optional)
• 3/4 cup shredded sharp cheddar cheese, divided 
• scallion, for garnish

Directions

1. Pre-heat oven to 400ºF.
2. Heat a large heavy bottom pan, over medium heat and melt butter. Add onion and celery cook until beginning to soften, about 5-7 minutes.
3. Add garlic, and cook for 30 seconds.
4. Sprinkle in arrowroot, and then slowly whisk in cashew milk (or milk of choice) a 1/2 cup at a time to avoid any lumps. (see note)
5. Add dijon mustard, salt, pepper, paprika and cayenne, if using, and whisk to combine.
6. Add cauliflower and simmer for 5 minutes, stirring occasionally. 
7. Remove from heat and stir in 1/2 cup of cheese. Then add in Genova Seafood Tuna, al dente cooked pasta (Omit for Low Carb Version), frozen peas and mix to fully combine.
8. Pour into an oven safe dish (if not using one already) and top with remaining 1/4 cup cheese and bake until cauliflower is tender and cheese is melted, 15-20 minutes. If you want the cheese to be bubbly and slightly browned, place under the broiler for 3-5 minutes.
9. Top with scallions and let sit for 5 minutes before serving.

Recipe Notes

1. The sauce may seem really thick before it goes in to the oven, but the cauliflower and the tuna exude a lot of liquid so the extra thick sauce stops it from becoming to0 watery after it is baked.

Loading nutrition data...

There may be affiliate links in this post! By clicking on them, or purchasing recommended items I may receive a small compensation, at no cost to you! However, I only recommend products I absolutely love and use in my own home! Thank you for supporting Lexi's Clean Kitchen when you shop! See my privacy policy for more information about this, the information we save, and more!